In an effort to address the growing market need for additional wireless services and related applications, future wireless communication standards (e.g., 5G networks) propose requirements that substantially increase the channel traffic capacity of wireless networks.
In recent years, multiple-input multiple-output (MIMO)-based communication systems have been implemented to accommodate and reliably support higher data rates and increased data streams for contemporary demands. However, the increase of channel traffic capacity, as required by the future standards, presents certain challenges to wireless networks, including MIMO-based communication systems.
For example, based on channel characteristics in addition to MIMO-based system parameters, such as, for example, carrier frequency, distance between transmitter and receiver sites, and distances among antenna elements of the transmit/receive antenna arrays, over time, the channel matrix may become ill-conditioned. That is, the channel matrix may have singular values with very small magnitudes in comparison to other singular values. Such an ill-conditioned channel matrix results in a significant degradation of the spectral efficiency of MIMO-based systems.